A classical treatment method for developmental dysplasia of the hip (DDH) is that if a child diagnosed with the developmental dysplasia of the hip is under 3 years old, it will needs to perform, under anesthesia, a manual reposition to put the hip joint back to a normal position, i.e. to perform a closed reduction, if successful, it needs a special gypsum (frog gypsum) so as to ensure that the hip joint is in a correct position. An overall treatment time by wearing the frog gypsum is nine months. The gypsum needs to be replaced under anesthesia every three months, total of three times, in order to adapt to the growth of child and ensure hardness of the gypsum, since as wearing time prolongs, the gypsum may become soft. The gypsum needs to be worn till the hip joint is restored to a normal position, nearly one year, then it can be removed. After the gypsum is removed, a special brace and physical therapy are required to enable muscles of hips and legs to recover gradually, and thus a travelling function is restored gradually.
The classical treatment method has the following disadvantages: repetitive anesthesia for more than three times, repetitive reduction and gypsum fixation; stiffness due to long term fixation, arrested development and developmental imbalance of the hip system; mal-development of concentric circles of the femoral head, and poor maintenance of stability of the hip joint.